Low doses of aspirin have long been used as a preventative tool against cardiovascular disease. Past research has shown that daily aspirin use can lower the chances of having your first heart attack or stroke in certain populations. But the regimen is not without risks, and new recommendations suggest doctors rethink its use.

In a draft statement, the US Preventive Services Task Force, an independent group of experts that advise on disease prevention and evidence-based medicine, have updated their recommendations, saying that for older adults, preemptively taking aspirin is not worth the risks. Specifically, the panel states that while starting on aspirin to prevent the onset of heart disease may be beneficial to younger adults (aged 40 to 59) on a case by case basis, adults aged 60 and older should not start the regimen. The risks of serious side effects for them, including bleeding in the stomach, intestines, and brain, aren’t worth the potential benefits, the panel states. 

The task force clarifies that its new recommendations only apply to those who have never had a heart attack or stroke before, and are not already regularly taking aspirin. But if you are 60 or older and have no history of cardiovascular disease, you should not begin on aspirin. 

“At that point, the higher risk of bleeding with age actually cancels out the potential benefit of aspirin,” Chien-Wen Tseng, a member of the task force and the research director of family medicine and community health at the University of Hawaii, told The Washington Post.

[Related: Why experts now say daily aspirin could do more harm than good]

Heart attacks happen when arteries, which supply blood to the heart, become clogged, cutting off the vital flow of blood to the heart, and strokes are a result of a blood clot cutting off flow to the brain. Heart disease is the leading cause of death in the US, responsible for 1 in 4 deaths, according to the US Centers for Disease Control and Prevention. Aspirin is an anticoagulant, a drug that thins the blood and therefore prevents blood clots from forming. While previous guidelines recommended taking a daily dose of aspirin to prevent cardiovascular disease—based on evidence from trials in the 1980s and 1990s—the new guidelines are not so cut and dry.

“There’s no longer a blanket statement that everybody who’s at increased risk for heart disease, even though they never had a heart attack, should be on aspirin,” Tseng told The New York Times. “We need to be smarter at matching primary prevention to the people who will benefit the most and have the least risk of harms.”

Those on aspirin already who think they should stop should consult their doctor. Tseng added, “We don’t recommend anyone stop without talking to a clinician, and definitely not if they have already had a heart attack or stroke.”
Donald Lloyd-Jones, president of the American Heart Association, told The Washington Post that the task force’s proposed updates were a “welcome adjustment,” and that the task force is “appropriately updating its recommendations on aspirin for primary prevention, specifically in response to changes in the evidence.” He added, “this is how science should work and should translate to clinical care.”